//
//  NSObject+KVO.h
//  KVO_Demo
//
//  Created by meitianhui2 on 2017/12/23.
//  Copyright © 2017年 DeLongYang. All rights reserved.
//

#import <Foundation/Foundation.h>
typedef void (^PGObservingBlock)(id observingObject,NSString *observedKey,id oldValue,id newValue);

@interface NSObject (KVO)

- (void)PG_addObserber:(NSObject *)observer
                forKey:(NSString *)key
             withBlock:(PGObservingBlock )block;


- (void)PG_removeObserver:(NSObject *)observer
                   forKey:(NSString *)key;
                                     
                                     
                                     
@end
